The present invention relates to a series of polyglycoside derivatives that contain silicone groups introduced into the molecule by reaction with the hydroxyl groups present in the alkyl polyglucoside molecule. The preferred products have more than one water-soluble group per molecule and are made with mild reagents to avoid discoloration and mal odor.
Commercial alkyl polyglycosides generally have a low degree of polymerization of polysaccharide, in the molecule. This results in a molecule that is of limited water solubility. The present invention is aimed at functionalizing the hydrophobic alkyl polyglycoside, by including in the molecule phosphate, sulfate, sulfosuccinate, and carboxylate functionalities. These products have been called xe2x80x9calkyl glycosides, alkyl glycosides, alkyl polyglycosides or alkyl polyglycosidesxe2x80x9d by many different authors. All refer to the same molecules.
Alkyl polyglycosides have been known for many years, having been first synthesized in the early 1900 by Emile Fischer. Despite this, the products were of little commercial interest until much later.
U.S. Pat. No. 4,393,203 issued Jul. 12, 1983 to Mao et al, incorporated herein by reference, disclose that long chain fatty alcohols can be removed from alkyl polysaccharide products in thin film evaporators to achieve fatty alcohol levels of less than about 2% without excessive discoloration of the alkyl polysaccharide. This allowed for a more cosmetically acceptable product to be developed that is more surface active. The presence of the free fatty alcohol in the mixture, allows for a more water-soluble product, by removing the water insoluble alcohol.
One of the most significant patents is U.S. Pat. No. 5,003,057 issued Mar. 26, 1991 to McCurry et al incorporated herein by reference, provides for a process for preparing glycosides from a source of saccharide moiety and an alcohol in the presence of a hydrophobic acid catalyst is provided. An example of such a catalyst is dinonylnaphthalenemonosulfonic acid. The use of such catalysts provides a number of process advantages, which includes the reduced production of polar by-products. Preferred glycosides produced by the process are higher alkyl glycosides useful as surfactants.
U.S. Pat. No. 3,598,865 (Lew) discloses the production of higher alkyl (C8-C25) glycosides from a monosaccharide or source thereof and a higher monohydric alcohol in the presence of a latent solvent (lower alcohols) and an acid catalyst selected from the group consisting of sulfuric acid, hydrochloric acid, phosphoric acid, phosphorous acid, toluenesulfonic acid, and boron trifluoride.
U.S. Pat. No. 3,219,656 (Boettner) discloses a process for producing a higher alkyl glycoside by reacting glucose with methanol in the presence of a macroreticular-structured sulfonic acid resin, anhydrous and in the acid form, to produce methyl glycoside which is reacted without isolation with butanol to form butyl glycoside and which in turn is reacted with a higher alcohol to form a surface active higher alkyl glycoside.
U.S. Pat. No. 3,839,319 (Mansfield) discloses a process for producing alkyl glycosides by direct, acid catalyzed reaction of a higher alcohol and a saccharide. The acid catalysts are mineral acids such as hydrochloric and sulfuric, and sulfonic acid exchange resins
U.S. Pat. No. 5,428,142 issued Jun. 27, 1995 to O""Lenick a series of silicone glycosides prepared by the reaction of a hydroxy containing dimethicone copolyol with a reducing saccharide, or a source of reducing saccharide, in the presence of a suitable catalyst. These materials contain no alkyl groups, having the silicone portion of the molecule replacing the alkyl group in alkyl polyglucoside. The present invention is aimed at taking an alkyl polyglucoside and in a subsequent step silicone functionalizing it, keeping the critical alkyl group present. The alkyl group has been found to be critical to the desired surfactant properties.
U.S. Pat. No. 5,498,703 to O""Lenick issued Mar. 12, 1996 discloses a series of silicone containing glycosides prepared by the reaction of a silanol with a reducing saccharide, or a source of reducing saccharide, in the presence of a suitable catalyst. These materials have no alkyl group in the molecule, having the silicone portion of the molecule replacing the alkyl group in alkyl polyglucoside. The present invention is aimed at taking the alkyl polyglucoside and in a subsequent step, silicone functionalizing it, keeping the critical alkyl group present. These materials have the silicone portion of the molecule replacing the alkyl group in alkyl polyglucoside. The present invention is aimed at taking the alkyl polyglucoside and silicone functionalizing it, with the critical alkyl group present.
The present invention relates to the finding that the reaction of the rather hydrophobic alkyl polyglycosides with the proper reagent results in molecules that have improved water-solubility and substantivity. Consequently they overcome many of the shortcomings of the alkyl polyglycosides itself. It is most interesting that the maximum amount of glycoside units per alkyl group that can be added using known technology is 1.5. This means that the product is a mixture of mono and di functional product. This product has the remaining fatty alcohol stripped off in an evaporative process. The resulting product is about 70% by weight of a product of a d.p. of 1, about 21% by weight of a product of a d.p. of 2, about 7% by weight of a product having a d.p. of 3, and about 2% by weight of a product that has a d.p. of 4.
We have surprisingly learned that taking the alkyl polyglycosides produced in the commercial process, with it""s inherent lack of water solubility and reacting it to make silicone functionalized surface-active agents, results in a series of products that are much more usable in many applications. Simply put, alkyl polyglycosides make much better hydrophobic raw materials than finished surface-active agents. When some or all of the many hydroxyl groups are converted into silicone functionalized groups, outstanding more widely applicable surface-active agents result.
Alkyl polyglycosides are complex products made by the reaction of glucose and fatty alcohol. In dealing with the chemistry one talks about degree of polymerization (the so called xe2x80x9cd.p.xe2x80x9d). In the case of traditional alkyl polyglycosides the d.p. is around 1.4. This means that on average thee is 1.4 units of glucose for each alkyl group. The fact of the matter is that the resulting material is a mixture having an average of 1.4.
The specific structure of the product is hard to ascertain completely since many positional isomers are possible, but two examples of structures are as follows; 
It should be clear that if there is a 50/50 mixture of the d.p. 1 and d.p. 2 product, the resulting analytical data will show that on average there is a d.p. of 1.5. Saying that a molecule has a d.p. of 1.5 does not mean that each molecule has 1.5 glucose units on it.
One key aspects of the present invention relates to the heretofore unappreciated fact that the rather hydrophobic alkyl polyglycosides contain on average five hydroxyl groups, one primary and the other four secondary. The assumption that there is a large degree of group specificity for the primary to react exclusively rather than the four additional hydroxyl groups is simply not true. This means that if on average only one of the five groups is reacted, there remains a very large concentration of reacting alkyl polyglycoside that has no functionality on it. Since the reactant with no functionalization remains water insoluble, there needs to be at lease 2 and as many as 4 hydroxyl groups functionalized to get to the desired water-soluble product. We have observed that when between 2 and 5 groups are reacted, a water-soluble very useful product results. Therefore it is a preferred embodiment having between 2 and 5 of the hydroxyl groups functionalized.
Another key unappreciated fact in making the compounds of the present invention is the selection of the proper reagents to make the desired product. Specifically, if aggressive conditions are used, the starting alkyl polyglycoside discolors and degrades quite seriously, making a large concentration of degradation products that are quite dark, smelly. Reaction of an aqueous alkyl polyglucoside with an epoxy silicone provides a facile method to obtain the desired product.
The compositions of the present invention are mixtures conform to the following structures: 
xe2x80x83wherein;
R is alkyl having 8 to 22 carbon atoms;
R1, R2, R3, and R4 are independently selected from the group consisting of 
and H, with the proviso that R1, R2, R3, and R4 are not all H;
a is an integer ranging from 0 to 1,000;
b is an integer ranging from 1 to 20;
c is an integer ranging from 0 to 20;
x, y and z are each integers independently ranging from 0 to 20;
and 
wherein;
R is alkyl having 8 to 22 carbon atoms;
R5, R6, R7, R8; R9 and R10 are independently selected from the group consisting of 
and H, with the proviso that R5, R6, R7, R8, R9 and R10 are not all H,
a is an integer ranging from 0 to 1,000;
b is an integer ranging from 1 to 20;
c is an integer ranging from 0 to 20;
x, y and z are each integers independently ranging from 0 to 20.
In a preferred embodiment c is 0.
In another preferred embodiment b is 1.
In another preferred embodiment b ranges from 2 to 10.
In another preferred embodiment c ranges from 2 to 10.
In another preferred embodiment R is C12H25.
In another preferred embodiment R is C10H21.
In another preferred embodiment R is C8H17.
In another preferred embodiment R is C14H27.
In another preferred embodiment R is C18H37.
In another preferred embodiment R is C18H35.
In another preferred embodiment R is C20H42.
In another preferred embodiment R is C22H42.
In another preferred embodiment a is an integer ranging from 1 to 200.
In another preferred embodiment a is 0.
In another preferred embodiment a is an integer ranging from 10 to 20.
In another preferred embodiment a is an integer ranging from 2 to 5.